Yagil R, Etzion Z, Berlyne G M
Lab Anim Sci. 1976 Feb;26(1):33-7.
The effects of variations in suckling stimulus (changes in letter size) and exposure to high ambient temperatures on the quality and quantity of rat's milk and mammary tissue structure were determined. By increasing the number of suckling pups per dam, it was found that the amount of milk produced by the animals was proportionally increased, as each pup was able to drink the same amount of milk per day. With more than 6 pups per litter, the quality of the milk was not significanly changed. Smaller letters led to changes in the amount of milk suckled per milking and to considerable changes in the content of the milk. Exposure to high ambient temperatures, although for only 8 hr per day, drastically affected the amount of milk produced by the lactating rat as well as the quality of the milk produced. Microscopic examination of mammary tissue revealed changes in the alveolar area and height of the alveolar cells as the suckling stimulus varied. After heat exposure the gland changed to one of diminished synthesizing capability. It was concluded that 10-pup litters are the optimal litter size for research concerning rat milk, and the exposure to high ambient temperatures affects the milk yield by directly affecting the alveolae.
研究了哺乳刺激变化（字母大小改变）和暴露于高温环境对大鼠乳汁质量和产量以及乳腺组织结构的影响。通过增加每只母鼠哺乳幼崽的数量，发现动物产奶量按比例增加，因为每只幼崽每天能喝到相同量的奶。每窝超过6只幼崽时，乳汁质量没有显著变化。较小的字母导致每次挤奶时吸食的奶量发生变化，并使乳汁成分发生显著变化。暴露于高温环境，尽管每天仅8小时，也会严重影响泌乳大鼠的产奶量以及所产乳汁的质量。随着哺乳刺激的变化，对乳腺组织的显微镜检查显示肺泡面积和肺泡细胞高度发生了变化。热暴露后，腺体转变为合成能力减弱的状态。得出的结论是，对于大鼠乳汁研究而言，10只幼崽的窝仔数是最佳窝仔数，暴露于高温环境会通过直接影响肺泡来影响产奶量。
